Dar, Go back and read what I said and then read your link again... Of the two pipes they used, one was used in F3A which is mostly WOT.

The other one, was one of the newer design Quiet Pipes which I was saying would have a broader torque range than the classic pipe. You will notice, however, that even the Quiet Pipe raised the Torque peak from 7200 to 8000. This pipe could be set up to your advantage in some less than WOT situations for it will really broaden the power band of the G 90. It would require careful selection of prop and airplane.

There are two opposing problems with the G 90 and a pipe. They go on and on in the link you provided about the conservative timing and small passages on the G 90 (giving it a low torque peak). This goes against the grain of any classic pipe theory that I ever read. They didn't mention it in the link but the last batch of G 90's produced in Italy had the same carb on it as they use on the G 40.

I have a couple of G 90's. If you put a 15-8 on one, it will have a peak static rpm around 9,000. It is the sickest sounding engine you ever heard from a spool up point of view. This is absolutely no good in a 3D situation. I'd rather use my Saito 100. Bax recommends a 13-6 for break in on a G 90 which is fine but you will notice that this is not enough prop for the engine because it will spin it close to 13,000 which also happens to oppose the Super Tiger link that you provided. I like the 14-6 on a G 90 for my kind of flying but a friend here locally, (that's also on RCU all the time), needed more speed in his war birds than what the 14-6 at 11,000 gave him, so he went to a 13-8.

As I said before, I think tuned mufflers and Quiet Pipes are nice, and I have several tuned mufflers, but I generally tend to opt for a more powerful engine rather than spending $50 to $100 for a exhaust pipe. A K&B 61 W/ std. muffler weighs less than a OS 46 FX with a Classic pipe and will out do it, performance wise, all across the board.

Pipes are most effectively used in competition whereby there is a displacement restriction. The competitors will use this maximum displacement engine with a pipe (And the Quiet Pipe, multiple chamber, types are most commonly used now days) To gain more power and competiveness in their flying.

In Western Europe where engines are required to have extra quiet mufflers, the classic single chamber pipe makes no sense at all in a none displacement restriction environment.

You are perfectly welcome to use a pipe if you so desire. I only have control over what I do and often wonder if I even do that very well?

Enjoy,

Jim